Motor sizing!!!

[bjkmiami]

Hello Everyone....
I am wondering how you choose kW rating of the motor in terms of compressor cooling capacity??(talking about open drive single screw ammonia compressor)..
For example what motor capacity i should pick for a compressor block with 300kW cooling capacity for given conditions???
Thanks in advance

[RANGER1]

Hello Everyone....
I am wondering how you choose kW rating of the motor in terms of compressor cooling capacity??(talking about open drive single screw ammonia compressor)..
For example what motor capacity i should pick for a compressor block with 300kW cooling capacity for given conditions???
Thanks in advance

Need compressor type exactly & conditions sct & sst, economizer, liquid injection cooling if used, speed etc

[bjkmiami]

Need compressor type exactly & conditions sct & sst, economizer, liquid injection cooling if used, speed etc

J&E Hall
speed:2980rpm
Full load capacity:275kW
suction mass flow rate:0.24kg/s
External oil cooling:37.5kW(no liquid injection)
No economizer
Design conditions -10C/+35C

[Peter_1]

At least 110 kW for NH3,

[bjkmiami]

At least 110 kW for NH3,
Hello Peter,
can you tell me the correlation between them please..how did you come up with that number?
Thanks.....

[Peter_1]

There's no exact correlation, as soon you change 1 parameter, needed power will change. I did a simulation via another brand.
You also can plot this on a log p/h chart and calculate it very precisely. Or you can use Coolpack or any other simulation like Solkane,...

[Josip]

Hi, bjkmiami :)


J&E Hall
speed:2980rpm
Full load capacity:275kW
suction mass flow rate:0.24kg/s
External oil cooling:37.5kW(no liquid injection)
No economizer
Design conditions -10C/+35C

For your capacity seems you need or have HSO 3220 compressor ... actual power consumption is about 72 kW (Q=272kW at -10/+35 NH3 data from J&H brochure), but you need to contact J&H and ask for compressor starting torque and then to order electrical motor with adequate starting and pull up torque otherwise you won't start the compressor (believe me-I was there) ... this is not a question only about motor power in kW ...

Check links below and see by yourself .... a lot to read, but worth all the time spent ...

http://www.johnsoncontrols.com/content/dam/WWW/jci/be/industrial_refrigeration/downloads/e70_-_610_sed.pdf page 14 ...

http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/6b4e1a3530814df0c12579bb0030e58b/$file/1sfc132060m0201.pdf

http://www.asercom.org/fileadmin/user_upload/downloads/Statements/11_ENG_Inverter_Guide-book.pdf

http://www.schneider-electric.hu/documents/automation-and-control/asg-3-motors-and-loads.pdf

http://www.fjb.co.uk/wp-content/themes/fjb/publications/large%20screw%20compressors.pdf

My suggestion is, if you are not sure what do you need ask someone for professional help ...

Hope this is of some help to you ..

Best regards, Josip :)